I can't really offer advice about how to record videos, since I'm more into screenshot LPs. But as for what game you want to do, it's best to pick your own game that you want to do. This will insure that you have the most to say about the game. For instance, if you want to play LoZ: OoT, you can have videos (with subtitles?) that shows off your reactions to the games, what you find interesting about it, or whatever else you can think of talking about.

People might suggest a game you would never have an interest in playing, and that won't make for an interesting LP from you, since you're not interested in the game, and it will be easy for viewers to see that.